What is metal stamping?
Metal stamping forms sheet metal into parts on a press: blanking, piercing, bending, drawing, coining and trimming. The tool decides which of those operations run in one stroke or across a sequence of stations, and the annual volume decides which tool type is worth building.
The five process routes
| Route | How it works | Fits |
|---|---|---|
| Single-hit stamping | One operation per stroke, part handled between operations | Low volume, prototypes, large parts |
| Progressive die stamping | All operations run in the strip, one station per stroke | High volume, small to medium parts |
| Transfer press stamping | Blank carried between stations by a transfer | Larger parts the strip cannot carry |
| Deep drawing | Flat blank formed into a seamless cup or housing | Housings, shells, sleeves, cups |
| Precision / fine blanking | Sheared edge produced in one operation | Parts needing a clean cut face without a secondary operation |
What decides the press tonnage
Tonnage comes from the shear or forming area multiplied by the material's strength, not from the part size alone. A small part in 3 mm stainless can need more tonnage than a larger part in 0.5 mm aluminium. Balford runs presses from 25 t to 350 t and draws up to Ø250 mm, so the tonnage question is answered against the drawing rather than against a catalogue table.
What drives the piece price
- Material utilisation - the strip layout and the coil width decide how many parts come out of a tonne, and that is often a bigger lever than the steel price itself.
- Number of operations - each operation added means a station, a longer tool, and often a higher tonnage press.
- Tolerance demand - a tight callout on a formed surface costs tooling effort; the same callout on a machined feature after stamping is usually cheaper to hold.
- Tool amortisation - the tool cost divided by the annual volume is part of the piece price, which is why volume changes the answer.
- Surface treatment - plating, phosphating, passivation and coating carry their own batch minimums and logistics.
Frequently asked questions
What is the difference between stamping and deep drawing?
Stamping is the family of press operations; deep drawing is one of them. A drawn part is normally finished by stamping operations such as trimming, piercing and flanging.
What is a typical tooling lead time?
For common single-operation or deep-draw programmes, in-house design and build typically runs 15–30 days; progressive and transfer dies take 30–60 days depending on station count and tryout iterations.
What sample lead time should I plan for?
From confirmed drawings, in natural days: about 30 days for a single-operation stamping die, 60 days for progressive die stamping, and about 15 days for CNC turning, sheet metal and tube bending. Rush orders can roughly halve that, subject to tooling complexity and material stock.
Can metal stamping hold tight tolerances?
Formed surfaces carry a different tolerance class from machined ones. Where a tight callout is genuinely needed, the feature is machined after stamping. Fine resolution - to 0.001 mm - applies only to selected key machined features and is confirmed against the drawing.